Are underground transmission lines feasible as an alternative to overhead transmission lines?

Although it is common to bury electric distribution lines that serve individual customers, it is rare to bury transmission lines. The per-mile construction cost is typically 5 to 10 times more than overhead lines and lifespan is generally about half as long. Reliability is also a concern. Typically, it would take at least a week to restore power in the event of an underground cable failure. GTC does evaluate the feasibility of underground transmission on a case-by-case basis. In addition, we help fund research into making underground transmission a viable option.